Which component stores energy in an electric field?

• A. Inductor
• B. Transformer
• C. Capacitor
• D. Resistor

Answer: (C)

Storing energy in an electric field happens when a capacitor is charged. Putting a voltage across two conductors separated by a dielectric causes charges to accumulate on the plates, creating an electric field in the space between them. The energy stored is in that field, and it can be released later when the capacitor supplies current. The amount of energy stored is given by 1/2 C V^2, so larger capacitance or higher voltage means more energy stored.

Inductors, on the other hand, store energy in a magnetic field produced by current flowing through a coil, and resistors simply dissipate energy as heat. Transformers mainly transfer energy between circuits via magnetic coupling rather than storing energy in an electric field.